Hi! Hello.

I’ve been into space mirrors — satellites with reflective surfaces that turn night into day — for a while. I’m not the only one into them; the idea has been around for over a century, and we can’t seem to quit the technology.

(They also pop up in unexpected places, including a fantasy novel I read — reply to this email if you want to know which one!)

Governments and/or corporations have considered them for various purposes, including controlling the weather, facilitating longer farming times, and… burning cities to the ground.

Even if you remove the last one, the idea of space mirrors disturbs me more than the satellites already swarming our planet. A visible spotlight shunting sun down upon us evokes a visceral response; you know when Big Mirror is watching, and there’s nothing you can do about it.

That hasn’t stopped several personalities from pursuing space mirrors, then and now. Scientists and engineers, backed by significant funders, have repeatedly tried to get them off the ground. Until now they’ve had limited success. But that might change in the near future… read on to learn about the odd dudes who’ve tried to make space mirrors a thing, what prevented their success, and whether their efforts are truly grounded.

The German physicist Hermann Oberth was the first to conceive of space mirrors in his 1923 paper, Die Rakete zu den Planetenräumen (The Rocket into Planetary Space). That book is best known today for launching (pun intended, sorry) modern space travel. In it, however, Orberth also talks about space mirrors made of metallic sodium that, when lined up in a chain, could create cities basked in eternal daylight.

Oberth, who worked for the Nazi government and was integral to the creation of the V-2 rockets that decimated London, also viewed the mirrors as a weapon of mass destruction. How? The same way a magnifying glass in the hands of a psychopath and/or a child burns an ant to death.

“The amount of energy rendered available by such a mirror is inconceivable,” a June 1936 article in Voice stated about Oberth’s mirrors. “With it the ice at the poles could be melted away, areas infected with insect pests could be sterilized quickly and thoroughly, and the draining of inland lakes and flooded areas would no longer be dependent upon the slow process of pumping.” Oberth estimated it would cost €20 million to make the mirrors, equivalent to $2.5 billion today.

The Nazi regime continued to work on a “sun gun,” but there’s good news! The math to make a mirror capable of roasting Earth doesn’t really play out. “The laws of optics would make it impossible to focus all the heat from such a mirror so accurately that it could be a really dangerous weapon, though if the mirror were made a good deal larger it might be able to make selected areas uncomfortably warm,” Arthur C. Clarke wrote in his 1951 book, The Exploration of Space.

Oberth, who worked for the U.S. Government after World War II, countered that a series of space mirrors 62 miles in diameter could cause ample destruction, but at this point killer space mirrors were moot: Humankind had invented the atomic bomb, which checked the box on giving its wielders the ability to obliterate civilization, making a Death Star-like space mirror redundant.

Oberth — who later in life was into telepathy, clairvoyance, and psychokinesis — also explained that mirrors could change the weather by making arctic regions warmer and ripe for “Man to settle there.” Dr. I.M. Levitt, director of Philadelphia’s Fels Planetarium, also touted space-mirror benefits. In a syndicated January 1954 newspaper article, he said that mirrors “can direct the radiation of the sun to a specific area and so increase evaporation.” Mirrors, Levitt said, could also bring light to towns that lose power after natural disasters, add additional crop cycles to boost food production, and break down smog.

The possibilities were intriguing, and in the 1960s, Levitt reported, NASA and the U.S. Department of Defense got on board the space-mirror train. The government focused on developing mirrors set 22,300 miles in synchronous orbit above Earth (i.e., they would stay in the same spot from our perspective on the ground) and beam back light 1.7 times as strong as a full moon. That project, however, didn’t get very far.

Flash forward to 1977, however, and Krafft A. Ehricke — another German rocket engineer involved in developing the V-2 rocket — submitted a multi-billion-dollar two-tiered proposal to the U.S. House of Representatives to fund space mirrors. The first tier — Lunetta — would have mirrors 22,000 miles above us and illuminate areas 10 to 100 times brighter than a full moon. (Why this brightness level differs from Levitt’s reporting isn’t clear to me… I’m guessing it’s the size of the mirrors.) Development would take 10 years and would cost $15 billion ($81.7 billion in 2026 dollars). Stage two — Soletta — would take 20 to 30 years and would cost $30 to $60 billion ($163 to $327 billion today).

Soletta, Ehricke claimed, would give us sun-level brightness and would be only 2,600 miles above Earth since the closer the mirror is, the smaller and more concentrated the light will be. He hoped the mirrors would also replace things like street lighting and also extend farm production. His efforts also stalled out, but other countries were looking at the technology.

The United States continued to flirt with space mirrors via a research project dubbed SOLARES, but never launched anything. Russia, however, did. As early as 1984, the country was building mirror prototypes  and by 1993, scientist Vladimir Syromiatnikov, who repurposed his idea of solar sails for mirrors, oversaw the launch of the prototype Znamya 2 from the Russian space station, Mir.

Znamya 2 was a success. The prototype unfurled its reflective sails, and a spotlight three miles in diameter as bright as a full moon skittered across Europe and Western Russia. Those on the ground reported seeing a “flash of light” on a cloudy night, and not much else.

Encouraged by the relative success of Znamya 2, Russia launched the slightly larger Znamya 2.5 in February 1999. That test was a failure. An antenna released at the wrong time tangled up the sails, and the mirror burned up in the atmosphere, never deployed. The failure along with growing complaints about the environmental and astronomical implications of such a system (more on that later!), killed not only Znamya 3, but the entire Russian project.

And yet the dream of space mirrors continued! In 2018, China was reportedly working on an “artificial moon,” but that also never made it to the sky.

Since then, it’s been quiet on the space mirror front… until the last two years. Recently, some startups are looking to make space mirrors a thing again, with companies like Meta getting in on the action. An then, of course, there’s the moon….

How? Why? I’ll get into all of it in next week’s post.